Nano-sized natural organic matter interacts with bisphenol A and decreases cytotoxicity to human cells

While the toxicity of pollutants has been rather well explored in simple laboratory conditions, there is little knowledge on their real toxicity in natural environments and living organisms because pollutants are often interacting and trapped into organic matter. Because of these interactions, their real concentrations can also be underestimated. Here we studied the nature, intensity, and strength of the interactions between bisphenol A and nano-sized natural organic matter. The bioavailability and toxicity of the complexed bisphenol A were tested with human colon adenocarcinoma cell lines. Results show that that interaction of bisphenol A with organic matter reduces bisphenol A cytotoxicity. Moreover, the bisphenol A-organic matter interaction is weak in the first hour then very stable after 24 h. Once formed, the bisphenol A-organic matter complex escapes detection and, as a consequence, the levels of pollutants in organic-rich media is most probably underestimated. The mechanism of interaction involves hydrophobic and π-stacking forces inside the core of nano-sized organic matter.